Input device, input method and program

ABSTRACT

An input device acquires information indicating a plurality of points on a touch panel affected by a user&#39;s touch, including the touch with a finger or a stylus, calculates distances between a reference position and at least some of the plurality of points, the reference position indicating a position touched by the user on the touch panel other than with the finger or the stylus, selects one or more points affected by the touch with the finger or the stylus from the at least some of the plurality of points based on the calculated distances, and acquires coordinates of a position indicated by the user based on the selected point.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and is a Division of U.S.application Ser. No. 14/651,225 filed on Jun. 11, 2015 which is aNational Stage of International Application No. PCT/JP2014/064507 filedon May 30, 2014, the content of which is hereby incorporated byreference into this application.

TECHNICAL FIELD

The present invention relates to an input device, an input method and aprogram.

BACKGROUND ART

It is increasing to enter characters and graphics with use of a touchpanel having a large touch-sensitive area, such as a tablet computer.When characters and graphics are input to a touch-sensitive area with afinger or a stylus, sometimes an edge of a hand on a little finger side,an edge of a palm above a wrist, or a wrist itself, which arecollectively referred to as “an edge of a little finger side or otherportions of a hand” or “a trunk of a hand” in the followings, comes intouch with the touch-sensitive area of the touch panel. If these partscome in touch with the touch-sensitive area of the touch panel, aposition of the finger or the stylus indicated by the user cannot bedetected.

In this regard, Patent Literature 1 discloses that a capacitive touchpanel detects whether or not a palm touches the touch panel using themaximum detected value at a certain detection point and detected valuesof detection points before and after the certain detection point, anddoes not generate coordinate data when the palm touches the touch panel.

CITATION LIST Patent Document

Patent Literature 1: JP2002-82765A

SUMMARY OF INVENTION Technical Problem

However, according to the known art mentioned above, generating thecoordinate data is stopped when the palm touches the touch panel, andthus a touched position of the fingertip or the stylus indicated by theuser cannot be detected.

One or more embodiments of the present invention have been conceived inview of the above, and an object thereof is to provide an input device,an input method, and a program for detecting a position indicated by auser with a finger, a stylus or the like even if an edge of a littlefinger side or other portions of a hand touches a touch-sensitive areaof a touch panel.

Solution to Problem

In order to solve the above described problems, an input deviceaccording to the present invention includes acquiring means foracquiring information indicating a plurality of points on a touch panelwhich are affected by one or more touches of a user, including a touchwith a finger or a stylus, distance calculating means for calculatingdistances between a reference position and at least some of theplurality of points, the reference position indicating a positiontouched by the user on the touch panel other than with the finger or thestylus, selecting means for selecting one or more points affected by thetouch with the finger or the stylus from the at least some of theplurality of points based on the calculated distances, and coordinateacquiring means for acquiring coordinates of a position indicated by theuser based on the selected one or more points.

An input method according to the present invention includes: acquiringinformation indicating a plurality of points on a touch panel which areaffected by one or more touches of a user, including a touch with afinger or a stylus, calculating distances between a reference positionand at least some of the plurality of points, the reference positionindicating a position touched by the user on the touch panel other thanwith the finger or the stylus, selecting one or more points affected bythe touch with the finger or the stylus from the at least some of theplurality of points based on the calculated distances, and acquiringcoordinates of a position indicated by the user based on the selectedone or more points.

A program according to the present invention causes a computer toexecute processing including acquiring information indicating aplurality of points on a touch panel which are affected by one or moretouches of a user, including a touch with a finger or a stylus,calculating distances between a reference position and at least some ofthe plurality of points, the reference position indicating a positiontouched by the user on the touch panel other than with the finger or thestylus, selecting one or more points affected by the touch with thefinger or the stylus from the at least some of the plurality of pointsbased on the calculated distances, and acquiring coordinates of aposition indicated by the user based on the selected one or more points.

According to the present invention, it is possible to reliably detect aposition indicated by a user with a finger or a stylus even if an edgeof a little finger side or other portions of a hand touches a touchpanel.

In an embodiment of the present invention, the input device furtherincludes determining means for determining whether or not there are aplurality of touches of the user on the touch panel, and referenceposition acquiring means for acquiring the reference position in a casewhere it is determined that there are the plurality of touches of theuser on the touch panel. The distance calculating means may calculatethe distances based on the acquired reference position, and theselecting means may select the one or more points based on thedistances.

In an embodiment of the present invention, the determining means maydetermine whether or not there are the plurality of touches based on avariance of the plurality of points.

In an embodiment of the present invention, the determining means maydetermine whether or not there are the plurality of touches of the userbased on a size of an area touched by the user.

In an embodiment of the present invention, the reference position may bethe center of gravity based on the plurality of points.

In an embodiment of the present invention, the plurality of pointsrespectively correspond to a plurality of portions on the touch panelwhere capacitance is measured.

In an embodiment of the present invention, the distance calculatingmeans may calculate the reference position based on respective positionsof the plurality of points and measurement values at the plurality ofpoints.

In an embodiment of the present invention, the plurality of points mayindicate positions of the plurality of touches of the user on the touchpanel.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an example of configuration of a touchpanel input device according to the first embodiment of the presentinvention.

FIG. 2 is a diagram illustrating an example a relationship between atouch-sensitive area of a touch panel and a hand in a case ofhandwriting input.

FIG. 3 is a diagram illustrating an example of measurement values ofcapacitance at respective measuring points.

FIG. 4 is a block diagram illustrating functions implemented by acoordinate calculating unit according to the first embodiment.

FIG. 5 is a flow chart showing an example of processing of thecoordinate calculating unit according to the first embodiment.

FIG. 6 is a diagram illustrating a relationship in distances between thereference position and the measuring points P in the example of FIG. 3.

FIG. 7 is a block diagram illustrating functions implemented by a host 2according to the second embodiment.

FIG. 8 is a flow chart showing an example of processing of a coordinateselecting unit.

FIG. 9 is a diagram illustrating an example of a relationship among thecoordinates of the calculated touched positions, the reference position,and the distances.

DESCRIPTION OF EMBODIMENTS

An embodiment of the present invention will be described below in detailwith reference to the accompanying drawings. The elements having thesame functions are designated with the same reference characters, andtheir overlapping explanation will be omitted.

First Embodiment

FIG. 1 is a diagram illustrating an example of configuration of a touchpanel input device according to the first embodiment of the presentinvention. The touch panel input device includes a touch panel 1, whichis a capacitive touch panel, and a host 2. Specifically, the touch panelinput device is a tablet computer and an electronic book reader, forexample.

The touch panel 1 includes scanning electrodes 10 disposedlongitudinally, detection electrodes 12 disposed laterally, a touchintensity detecting unit 21 that detects signals indicating touchintensity of measuring portions C at respective portions where thescanning electrodes 10 and the detection electrodes 12 intersect, and acoordinate calculating unit 22. The touch panel 1 is a capacitive touchpanel.

The host 2 includes a processor 31, a storage unit 32, a communicationunit 33, and a display unit 34. The processor 31 executes a programstored in the storage unit 32, and controls the communication unit 33and the display unit 34. The program may be provided via the Internet orby being stored in a computer-readable storage medium such as a flashmemory.

The storage unit 32 includes a memory device such as a RAM or a flashmemory, and a hard disk drive. The storage unit 32 stores the program.In addition, the storage unit 32 stores information and computationalresult input from each unit.

The communication unit 33 implements functions to communicate with otherdevices, and includes an integrated circuit constituting a wireless LANand an antenna, for example. The communication unit 33 inputsinformation received from other devices into the processor 31 and thestorage unit 32, and sends information to other devices under thecontrol of the processor 31.

The display unit 34 includes a display output device and a videocontroller that controls the display output device. The display unit 34outputs display data to the display output device under the control ofthe processor 31. The display output device may be connected outside ofthe touch panel input device.

Next, the touch panel 1 will be explained. The scanning electrodes 10respectively extend in a horizontal direction of FIG. 1, and edges ofthe scanning electrodes 10 are connected to the touch intensitydetecting unit 21 by wiring. The detection electrodes 12 respectivelyextend in a vertical direction of FIG. 1, and each edge of the detectionelectrodes is connected to the touch intensity detecting unit 21 bywiring. The measuring portions C are respectively placed at thepositions where the scanning electrodes 10 and the detection electrodes12 intersect. The touch intensity is a degree of proximity or contact.The measuring portions C are m×n matrix. In FIG. 1, a measuring portionC at ith row and jth column is described as Cij. For example, themeasuring portion C11 is at the first row and the first column, and themeasuring portion C1 m is at the first row and mth column. The measuringportions C are disposed within the touch-sensitive area 14 of the touchpanel. In the following, a representative position (e.g., center) of themeasuring portion Cij is described as measuring point Pij.

The touch intensity detecting unit 21 includes a scanning circuit thatrepeats, for each frame period, providing the scanning electrodes 10with pulse signals in sequence, and a signal acquiring circuit thatacquires a signal having touch intensity according to changes in mutualcapacitance when the pulse is provided and makes AD conversion of theacquired signal of the touch intensity into data signal. When thescanning circuit applies a pulse to one of the scanning electrodes 10,the signal acquiring circuit outputs a data signal indicating touchintensity of the measuring portions C at the positions where the appliedscanning electrode 10 intersects the detection electrodes 12. When thescanning circuit finishes scanning of all of the scanning electrodes 10for one time each, the signal acquiring circuit outputs data signalsindicating touch intensity of respective measuring portions C in theframe period. Here, one frame period corresponds to a sampling period oftouch intensity.

FIG. 2 is a diagram illustrating an example of a relationship betweenthe touch-sensitive area 14 of the touch panel and a hand in a case ofhandwriting input. When inputting by handwriting, a user makes pluraltouches on the touch-sensitive area 14 of the touch panel. Morespecifically, the user's stylus or finger, which indicates a position,touches the touch-sensitive area 14. In addition, a portion of the handcloser to the base of the hand (wrist) than the finger indicating theposition or the fingers holding the stylus touches the touch-sensitivearea 14. Such portion of the hand is, for example, an edge of a hand ona little finger side, a portion of a palm closer to a wrist thanfingers, and a wrist itself, and a portion that touches thetouch-sensitive area 14 to stabilize movement of a stylus or a fingerwhen a user moves it.

FIG. 3 is a diagram illustrating an example of measurement values ofcapacitance at respective measuring points P. In FIG. 3, the measurementvalues are represented by a contour line graph. FIG. 3 represents thatthe values increase in the order of a dashed line, a thin solid line,and a thick solid line. For example, the dashed line indicates a valuelarger than a typical value of noise, and the thin solid line indicatessuch a value that is inevitably generated at the center of the touch. Acircular area on the left side of FIG. 3 indicates peaks of themeasurement values generated by touches of the stylus, and the contourlines in a larger area on the right side indicates peaks of themeasurement values generated by, for example, touches of the edge of thehand on the little finger side.

As can be seen by the above discussion of FIG. 3, when the finger or thestylus and other portion of the hand (the edge of the little finger sideof the hand, the edge of the palm near the wrist, and the wrist itself)closer than the finger touches the touch-sensitive area 14 of the touchpanel 1, the touch intensity detecting unit 21 acquires a signalindicating the measuring points P affected by the touches. In fact, themeasurement values of the measuring points P affected by the touchesindicate values greater than a noise threshold value for distinguishingthe values from a noise value.

In a case where characters are input, for example, a user rarely touchesthe touch-sensitive area such that the stylus or the finger indicating aposition comes closer to the portion of the hand such as the edge of thehand on the little finger side. As such, a position touched by thestylus, for example, tends to be farther away from anywhere in the largearea touched by the edge of the hand on the little finger side thanother points in the large area. For example, in FIG. 2, a distancebetween the upper and lower edges of an area touched by the edge of thehand on the little finger side is smaller than a distance between apoint in the area touched by the edge of the hand on the little fingerside and a position touched by the stylus or the like.

The coordinate calculating unit 22 calculates coordinates of theposition indicated by the user with the stylus or the finger based onthe measurement values of touch intensity detected by the touchintensity detecting unit 21 at respective measuring points P. Thecoordinate calculating unit 22 may be implemented by an integratedcircuit including a storage unit, such as a memory, and a processor (notshown). In the following, a case is explained where the coordinatecalculating unit 22 is implemented by such integrated circuit. Thecoordinate calculating unit 22 may also be implemented by a digitalcircuit requiring no program.

FIG. 4 is a block diagram illustrating functions implemented by thecoordinate calculating unit 22 according to the first embodiment. Thecoordinate calculating unit 22 functionally includes a multi-touchdetermining unit 41, a reference position acquiring unit 42, a distancecalculating unit 43, a measuring point selecting unit 44, and a touchcoordinate acquiring unit 45. These units are implemented by theprocessor executing a program stored in a storage unit andsending/receiving data to/from other circuits via a bus, for example.The program is stored in a memory in advance, but may be providedthrough the Internet, for example, or a storage medium, such as a flashmemory. In the following, these functions are explained with referenceto processing flow charts.

FIG. 5 is a flow chart showing an example of processing of thecoordinate calculating unit 22 according to the first embodiment. First,the coordinate calculating unit 22 obtains measurement values ofparasitic capacitance at the measuring points P from the touch intensitydetecting unit 21 (step S101).

Next, the multi-touch determining unit 41 included in the coordinatecalculating unit 22 determines whether multiple touches are made on thetouch-sensitive area 14 of the touch panel, based on the obtainedmeasurement values of parasitic capacitance (step S102). Morespecifically, for example, the multi-touch determining unit 41 maycalculate the variance of x coordinates of the measuring points P thatare larger than a determination threshold value, and determine thatthere are multiple touches if the variance is larger than adetermination reference value. The determination threshold value islarger than the maximum value of minute noise included in themeasurement values. Further, the determination threshold value may belarger than the noise threshold value for distinguishing noise. Themulti-touch determining unit 41 may count the number of the measuringpoints P that exceed the determination threshold value, therebycalculating the touched area, and determine that there are multipletouches if the calculated area is larger than the predetermined value.Alternatively, the multi-touch determining unit 41 may determine thatthere are multiple touches if the multi-touch determining unit 41 candivide the area including all of the measuring points P into a pluralityof area using a known Watershed algorism.

If it is determined that there are not multiple touches (“N” in stepS103), the one touch is only made, and thus the measuring pointselecting unit 44 included in the coordinate calculating unit 22 selectsall of the measuring points P for being used to calculate thecoordinates (step S110), and proceed to processing of S107 andsubsequent steps.

If it is determined that there are multiple touches (“Y” in step S103),the reference position acquiring unit 42 included in the coordinatecalculating unit 22 calculates a reference position. More specifically,the reference position acquiring unit 42 acquires the center of gravityof the measuring points P as the reference position based on thecoordinates and the measurement values of the measuring points P (stepS104). The reference position acquiring unit 42 may take the respectivemeasurement values of the measuring points P as a weight to calculatethe center of gravity, or assume the weight of the measuring points Pthat exceed the predetermined threshold value as 1 (predetermined value)and the weight of other measuring points P as 0 to calculate the centerof gravity.

The reference position is a position that represents the positions ofthe finger and the edge of the hand on the little finger side (orwrist). The area of the touch-sensitive area 14 touched by the edge ofthe hand on the little finger side is larger than the area touched bythe stylus or the like. As such, the number of the measuring pointsaffected by the touch of the edge of the little finger side or otherportions of the hand is remarkably greater than the number of themeasuring points affected by the touch of the stylus or the like. Thecalculated center of gravity is a position in the area touched by theedge of the little finger side or other portions of the hand, or aposition slightly deviated from such area, and thus can be regarded asthe position that represents the positions of the edge of the littlefinger side or other portions of the hand.

The reference position acquiring unit 42 may acquire the referenceposition in a different way. For example, information on whether theuser is right-handed or left-handed may be stored in the memorybeforehand, and if the user is right-handed, the reference positionacquiring unit 42 may calculate predetermined first coordinates at thelower right with respect to the center as the reference position, and ifthe user is left-handed, calculate predetermined second coordinates atthe lower left with respect to the center as the reference position. Forexample, if the user is right-handed, the right edge and lower half ofthe touch-sensitive area 14 is highly likely to be touched by the edgeof the hand on the little finger side, and thus the reference positionacquiring unit 42 may also acquire a fixed position at the lower rightof the touch-sensitive area 14 as the position (reference position) thatrepresents the positions of the edge of the little finger side or otherportions of the hand. Alternatively, the area may be divided into subareas, such as four areas, and the reference position acquiring unit 42included in the coordinate calculating unit 22 may calculate, as thereference position, the coordinates of a point (e.g., center) thatrepresents the sub area, in which the largest average value of themeasurement values of the measuring points P is achieved (the sum of themeasurement values may be used in a case where the number of themeasuring point P is the same among the sub areas).

When the reference position is acquired, the distance calculating unit43 included in the coordinate calculating unit 22 calculates a distancebetween each of the measuring points P having the measurement valuelarger than a calculated threshold value and the reference position(step S105). Subsequently, the measuring point selecting unit 44included in the coordinate calculating unit 22 selects, among from themeasuring points P, the measuring point P with its calculated distancefrom the reference position being the longest as one of the measuringpoints P to be used for calculating the touched coordinates (step S106).Here, the calculated threshold value may be enough if it is a value thatis certainly detected at the center of each touch. The referenceposition is considered to correspond to the position of the edge of thehand on the little finger side or the wrist, and thus, the measuringpoint P farthest from the reference position is considered to havecapacitance generated by the stylus or the finger. As such, themeasuring point P selected by the coordinate calculating unit 22 isexpected to be in the vicinity of the position of the stylus or thefinger.

FIG. 6 is a diagram illustrating a relationship in distances between thereference position R and the measuring points P in the example of FIG.3. Assume that the calculated threshold value is represented in a thinsolid line in FIG. 6, the measuring points P57, P58, P62, P68, P78, andP88 each has the measurement value larger than the calculated thresholdvalue. In the example of FIG. 6, the coordinate calculating unit 22calculates distances L1, L2, L3, L4, L5, and L6 between the respectivemeasuring points P and the reference position R, and selects themeasuring point P62 at which the longest distance L3 is calculated.

The measuring point selecting unit 44 further selects measuring points Paround the selected measuring point P as the measuring points P to beused for calculating the touched coordinates (step S107). In this way,all of the measuring points P used for calculating the coordinates areselected. The surrounding measuring points P may be measuring points Phaving predetermined positions relative to the selected farthest point,such as, eight measuring points P surrounding the selected pointfarthest from the reference position. Further, the measuring pointselecting unit 44 may select, as the measuring points P to be used forcalculating the touched coordinates, the measuring points P that belongto an area, which is one of the areas obtained by dividing thetouch-sensitive area 14 using the Watershed algorism and the measurementvalues and includes the measuring point P at which the longest distanceis calculated.

When the measuring points P to be used for calculating the coordinatesare selected, the touch coordinate acquiring unit 45 included in thecoordinate calculating unit 22 calculates, using the selected measuringpoints P, the coordinates of the touched position indicated by the userwith the stylus or the finger (step S108). Specifically, the touchcoordinate acquiring unit 45 acquires the center of gravity, which iscalculated by using the measurement values of the selected measuringpoints Pas the weight, as the coordinates of the touched positionindicated by the user. Alternatively, by using other methods, the touchcoordinate acquiring unit 45 may acquire the coordinates of the positionindicated by the user based on the measurement values of the selectedmeasuring points P. The coordinate calculating unit 22 then outputs thecalculated coordinates to the host 2 (step S109).

The processor 31, the storage unit 32, the communication unit 33, andthe display unit 34 included in the host 2 implement the functions tooutput images to, for example, the display output device of the displayunit 34, by executing the program stored in the storage unit 32according to the coordinates of the touched position indicated by theuser, which are calculated by the coordinate calculating unit 22.

As discussed above, using a relatively simple algorism where thereference position is calculated and the measuring point P farthest fromthe calculated reference position is selected, it is possible to detectcoordinates indicated by the user's finger or stylus by eliminatinginfluence of the touch with the edge of the little finger side or otherportions of the hand. The complicated processing, such as clustering, isnot employed here, and thus hardware incorporated in the touch panel 1can easily eliminate the influence of the edge of the hand on the littlefinger side, although processing capacity of such hardware is typicallydifficult to be improved.

Second Embodiment

In the first embodiment, the measuring point P that exceeds thecalculated threshold value and is farthest from the reference positionis selected among from the measuring points P on the predeterminedpositions on the touch-sensitive area 14 of the touch panel 1, and thecoordinates indicated by the user are determined based on the selectedmeasuring point P. Here, it is not necessarily a measuring point P thatis selected. In the second embodiment, a point farthest from thereference position is selected from the points whose coordinates arecalculated as the touched positions. In the following, differencesbetween the first embodiment and the second embodiment are mainlyexplained.

The touch panel input device according to the second embodiment includesa touch panel 1, which is a capacitive touch panel, and a host 2,similarly to the first embodiment. The hardware configuration of thetouch panel 1 and the host 2 is the same as the first embodiment.

The processing of the coordinate calculating unit 22 according to thesecond embodiment is different from the first embodiment. The coordinatecalculating unit 22 calculates the coordinates of one or more touchedpositions for each of objects that have touched, based on themeasurement values of the measuring points P detected by the touchintensity detecting unit 21. For example, when some objects touch thetouch-sensitive area 14 or a large object, such as an edge of a hand ona little finger side, touches the touch-sensitive area 14, coordinatesof a plurality of touched positions are calculated, and when a smallobject, such as a stylus or a finger, touches the touch-sensitive area14, coordinates of one touched position are calculated. For example,when the stylus and the edge of the hand on the little finger side arein contact with the touch-sensitive area 14, coordinates of touchedposition of the stylus and coordinates of a plurality of touchedpositions of the edge of the hand on the little finger side arecalculated. More specifically, the coordinate calculating unit 22divides the touch-sensitive area 14 using a known Watershed algorism,and determines coordinates of touched positions in each of the dividedtouch-sensitive areas 14, thereby calculating the coordinates of thetouched positions. In a case where the coordinate calculating unit 22cannot divide the touch-sensitive area 14, the measurement values of allof the measuring points P on the touch-sensitive area 14 are used forcalculating coordinates of one touched position.

As the example of FIG. 3 shows, when the measurement values aredistributed, three touch coordinates respectively corresponding to threepoints including a peak near the measuring point P62, a peak near themeasuring point P18, and a peak near the measuring point P88 arecalculated. The coordinate calculating unit 22 outputs the coordinatesof the calculated one or more touched positions to the host 2.

FIG. 7 is a block diagram illustrating functions implemented by the host2 according to the second embodiment. The host 2 functionally includes acoordinate selecting unit 51 and an application unit 52. The coordinateselecting unit 51 includes a calculation result acquiring unit 61, amulti-touch determining unit 62, a reference position acquiring unit 63,a distance calculating unit 64, a touched position selecting unit 65,and a touch coordinate acquiring unit 66. These functions areimplemented by the processor 31 executing a program stored in thestorage unit 32 and controlling the communication unit 33 and thedisplay unit 34, for example. The program may be provided through theInternet, for example, or by being stored in a computer-readable storagemedium, such as a flash memory.

FIG. 8 is a flow chart showing an example of processing of thecoordinate selecting unit 51. The coordinate selecting unit 51 is mainlyimplemented by the processor 31 and the storage unit 32. First, thecalculation result acquiring unit 61 included in the coordinateselecting unit 51 acquires coordinates of one or more touched positionsoutput by the coordinate calculating unit 22 via a bus (step S201).Second, the multi-touch determining unit 62 included in the coordinateselecting unit 51 determines whether the edge of the hand on the littlefinger side or the wrist touches based on the number of touchedpositions whose coordinates are calculated by the coordinate calculatingunit 22 (step S202). If the number of the touched positions is less thanthree (“N” in step S202), the touched position selecting unit 65included in the coordinate selecting unit 51 acquires all of the touchedposition as output target, and the touch coordinate acquiring unit 66included in the coordinate selecting unit 51 passes the coordinates ofall of the acquired touched positions to the application unit 52 (stepS207).

On the other hand, if the number of the touched positions is three ormore (“N” in step S202), the reference position acquiring unit 63included in the coordinate selecting unit 51 calculates the referenceposition in order to select one of the touched positions. Morespecifically, the reference position acquiring unit 63 calculates thecenter of gravity of the acquired three or more touched positions as thereference position (step S203). The distance calculating unit 64included in the coordinate selecting unit 51 calculates a distancebetween each of the touched positions and the reference position (stepS204), and the touched position selecting unit 65 included in thecoordinate selecting unit 51 selects the touched position having thelongest calculated distance (step S205).

Here, the reference position may not necessarily be the center ofgravity. For example, as discussed in the first embodiment, it may be aposition that is determined according to the predetermined dominant handof the user.

FIG. 9 is a diagram illustrating an example of a relationship among thecoordinates of the calculated touched positions X1, X2, and X3, thereference position Xc, and the distances D1, D2, and D3. FIG. 9 showsthe touched positions X1-X3 that are calculated by the coordinatecalculating unit 22 when the measurement values shown in FIG. 3 aremeasured. The touched position X1 corresponds to the position of thestylus in FIG. 2, and the touched positions X2 and X3 correspond topositions of two points on which stronger touch intensity is detectedamong the positions touched by the edge of the hand on the little fingerside. Typically, a plurality of points are detected in the edge of thehand on the little finger side or the wrist, which have larger areas. InFIG. 9, the reference position Xc is the center of gravity of thetouched positions X1-X3, and a position closer to the edge of the handon the little finger side, as with the first embodiment. As such, thedistance D1 is the longest among the distances D1-D3 between thereference position Xc and the touched positions X1-X3, and thus thetouched position X1 is selected.

When the touched position is selected, the coordinate selecting unit 51acquires the coordinates of the selected touched position, and passesthe acquired coordinates to the application unit 52 (step S206).

The application unit 52 is implemented by, for example, a processor 31,a storage unit 32, a communication unit 33, and a display unit 34. Theapplication unit 52 is implemented by the processor 31 executing anapplication program, determines characters and instructions that areinput based on the coordinates of the touched positions output by thecoordinate selecting unit 51, and executes processing for, for example,displaying images according to the characters and the instructions.

The touch panel input device according to the first embodiment and thesecond embodiment enables detecting a position indicated by the userwith the finger or the stylus even though the edge on the little fingerside or other portions of the hand touch the touch panel while the userinputs characters or the like.

The present invention may be applied to other devices than a tabletcomputer or an electronic book reader. For example, the touch panelinput device may be an external touch panel that is connected to apersonal computer, for example, or a touch panel provided as a componentwithout including the host 2.

REFERENCE SIGNS LIST

1 touch panel, 2 host, 10 scanning electrode, 12 detection electrode, 14touch-sensitive area, 21 touch intensity detecting unit, 22 coordinatecalculating unit, 31 processor, 32 storage unit, 33 communication unit,34 display unit, 41,62 multi-touch determining unit, 42,63 referenceposition acquiring unit, 43,64 distance calculating unit, 44 measuringpoint selecting unit, 45,66 touch coordinate acquiring unit, 51coordinate selecting unit, 52 application unit, 61 calculation resultacquiring unit, 65 touched position selecting unit, C measuring portion,P measuring point, L1,L2,L3,L4,L5,L6,D1,D2,D3 distance, R,Xc referenceposition, X1,X2,X3 touched position.

What is claimed is:
 1. An input method, comprising: acquiringinformation indicating a plurality of points on a touch panel affectedby one or more touches of a user of an input device, including a touchwith a finger of the user or a stylus; calculating distances between areference position and at least some of the plurality of points, thereference position indicating a position of a user touch of the inputdevice on the touch panel other than with the finger and other than withthe stylus; selecting a point, from the at least some of the pluralityof points, which has a largest calculated distance from the calculateddistances; acquiring coordinates of a second position indicated by theuser of the input device based on the selected point; and wherein, inthe point selection, one or more points around the selected point areselected as points affected by the touch with the finger or the stylus.2. The input method according to claim 1, further comprising:determining whether or not a number of the one or more touches of theuser of the input device on the touch panel is more than one; andacquiring the reference position when it is determined that the numberof the one or more touches of the user of the input device on the touchpanel is more than one, wherein the calculation of the distances isbased on the acquired reference position, and wherein the pointselection is based on the calculated distances between the referenceposition and the at least some of the plurality of points.
 3. The inputmethod according to claim 2, wherein, in the determination, whether ornot the number of the one or more touches of the user of the inputdevice on the touch panel is more than one, is determined based on avariance of the plurality of points affected by one or more touches ofthe user of the input device.
 4. The input method according to claim 2,wherein, in the determination, whether or not the number of the one ormore touches of the user of the input device on the touch panel is morethan one, is determined based on a size of an area touched by the user.5. The input method according to claim 1, wherein the reference positionis a center of gravity based on the plurality of points affected by oneor more touches of the user of the input device.
 6. The input methodaccording to claim 1, wherein the plurality of points affected by one ormore touches of the user of the input device respectively correspond toa plurality of portions on the touch panel where a capacitance ismeasured.
 7. The input method according to claim 6, wherein thereference position is calculated based on respective positions of theplurality of portions on the touch panel and measurement values at theplurality of portions.
 8. The input method according to claim 1, whereineach of the plurality of points affected by one or more touches of theuser of the input device each indicate a different position affected bythe one or more touches of the user of the input device.
 9. Anon-transitory computer-readable storage medium having stored thereon aprogram for causing a computer to execute processing, the processingcomprising: acquiring information indicating a plurality of points on atouch panel affected by one or more touches of a user of an inputdevice, including a touch with a finger of the user or a stylus;calculating distances between a reference position and at least some ofthe plurality of points, the reference position indicating a position ofa user touch of the input device on the touch panel other than with thefinger and other than with the stylus; selecting a point, from the atleast some of the plurality of points, which has a largest calculateddistance from the calculated distances; acquiring coordinates of asecond position indicated by the user of the input device based on theselected point; and wherein, in the point selection, one or more pointsaround the selected point are selected as points affected by the touchwith the finger or the stylus.
 10. The non-transitory computer-readablestorage medium according to claim 9, the processing further comprising:determining whether or not a number of the one or more touches of theuser of the input device on the touch panel is more than one; andacquiring the reference position when it is determined that the numberof the one or more touches of the user of the input device on the touchpanel is more than one, wherein the calculation of the distances isbased on the acquired reference position, and wherein the pointselection is based on the calculated distances between the referenceposition and the at least some of the plurality of points.
 11. Thenon-transitory computer-readable storage medium according to claim 10,wherein, in the determination, whether or not the number of the one ormore touches of the user of the input device on the touch panel is morethan one, is determined based on a variance of the plurality of pointsaffected by one or more touches of the user of the input device.
 12. Thenon-transitory computer-readable storage medium according to claim 10,wherein, in the determination, whether or not the number of the one ormore touches of the user of the input device on the touch panel is morethan one, is determined based on a size of an area touched by the user.13. The non-transitory computer-readable storage medium according toclaim 9, wherein the reference position is a center of gravity based onthe plurality of points affected by one or more touches of the user ofthe input device.
 14. The non-transitory computer-readable storagemedium according to claim 9, wherein the plurality of points affected byone or more touches of the user of the input device respectivelycorrespond to a plurality of portions on the touch panel where acapacitance is measured.
 15. The non-transitory computer-readablestorage medium according to claim 14, wherein the reference position iscalculated based on respective positions of the plurality of portions onthe touch panel and measurement values at the plurality of portions. 16.The non-transitory computer-readable storage medium according to claim9, where each of the plurality of points affected by one or more touchesof the user of the input device each indicate a different positionaffected by the one or more touches of the user of the input device.